The subject matter disclosed herein relates generally to medical diagnostic imaging systems, and more particularly, to diagnostic imaging systems that acquire bone and tissue information.
Characteristics of an individual, such as body weight, fat mass, height, girth, gender, age, etc. are clinical descriptors useful by physicians to predict certain health risks that may increase or decrease mortality and morbidity risk. For example, the amount or type of abdominal fat, such as subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) are associated with, and useful predictors of, an adverse metabolic risk profile and certain diseases, such as coronary heart disease and diabetes. In addition, measuring visceral fat, for example, can relate to metabolic syndrome—i.e., a combination of medical problems that can increase the risk of heart disease and/or diabetes. People suffering from metabolic syndrome can have some or all of the following: high blood glucose, high blood pressure, abdominal obesity, low HDL elevated cholesterol, and/or high triglycerides.
Conventional methods for measuring VAT are mostly performed using anthropomorphic gauges, bioimpedance gauges, weight scales, etc. These devices often are not capable of providing accurate measurements because the actual fat content is not being measured, certain assumptions/estimates are made during the calculation process, and/or the devices are not exactly calibrated. Also, reproducibility may be difficult, leading to inaccurate comparisons between examinations.
Imaging systems have also been used to measure VAT content. However, examination with these systems are often costly and can expose a patient to high levels of ionizing radiation, for example, when using a computed-tomography (CT) system. Additionally, these systems are not always available for clinical use and may have long scan times. Moreover, certain measurements are inaccurate in larger subjects.
Conventional methods for determining VAT often also use simple models to approximate the abdominal cavity from an estimate of subcutaneous thickness measurements. These methods can often fail to accurately estimate the SAT, thereby resulting in an inaccurate estimate of the VAT.